Alphabet's GOOGL.O Google faces an EU antitrust investigation into its use of web publishers' online content and YouTube videos to train its artificial intelligence models, the European Commission said on Tuesday.

The Commission, which acts as the EU competition enforcer, said it was concerned that Google may be using publishers' online content without compensating them adequately and without giving them the option to refuse the use of their content.

It expressed the same concerns regarding Google's use of YouTube videos uploaded by its users.

"Google may be abusing its dominant position as a search engine to impose unfair trading conditions on publishers by using their online content to provide its own AI-powered services such as 'AI Overviews', which are AI-generated summaries," EU antitrust chief Teresa Ribera told a conference.

"This case is once again a strong signal of our commitment to protecting the online press and other content creators, and to ensuring fair competition in emerging AI markets," she said.

Last week, the European Commission launched an investigation into Meta's plans to block AI rivals from its WhatsApp messaging system, underscoring increasing regulatory scrutiny into this area.

The U.S. tech giant risks a fine as much as 10% of its global annual revenue if found guilty of breaching EU antitrust rules.

Google's AI Overviews are AI-generated summaries that appear above traditional hyperlinks to relevant webpages and are shown to users in more than 100 countries. It began adding advertisements to AI Overviews last May.

The EU investigation into Google followed a complaint by independent publishers in July.